The nuclear
DNA content in 48
chondrosarcomas and 4
chondromas was determined. Grading according to O'Neal-Ackerman was also performed. All
chondromas were found to be diploid (normal nuclear
DNA content). Twenty-two of the
chondrosarcomas showed the same
DNA distribution curve as the
chondromas and were characterized as diploid, while 26 were found to be hyperploid (increased nuclear
DNA content). A comparative study of grade and ploidy in relation to ten-year survival and
metastasis rates showed that ploidy determinations in
chondrosarcomas give significant prognostic information, even better than that obtained by conventional histopathologic grading. In this study, diploid
chondrosarcomas were found to be associated with a significantly more favorable
clinical course than were hyperploid
chondrosarcomas. The prognostic relevance of these ploidy determination was further confirmed by analyzing the ploidy level of selected cases characterized bydifferent clinical courses. Thus, the
tumors from 13 (93%) of 14 patients with a highly malignant
clinical course (death within two years) and the
tumors at the primary site in 17 (81%) of 21 metastasizing
chondrosarcomas were found to be hyperploid. Direct measurements on four
metastases revealed that all were hyperploid.